This invention relates to methods and apparatus for the formation of a thin noble metal film by a plasma-excited vapor phase growth process.
Moreover, this invention also relates to apparatus and methods for forming a metal film on a substrate surface by a vapor phase growth process.
Furthermore, this invention also relates to apparatus for the vapor phase growth of a thin copper film which are useful, for example, in the formation of wiring material films for use in semiconductor devices.
Conventionally, where it is desired to form a thin noble metal film by a vapor phase growth process, such a film has been formed by the utilization of a thermal reaction using a liquid organometallic complex, such as copper hexafluoroacetylacetonato-trimethylvinylsilane [hereinafter referred to as Cu(hfac)(tmvs)], as a raw material.
FIG. 22 is a schematic view of a conventional apparatus 500 for the vapor phase growth of a thin noble metal film. The method for forming a thin noble metal film 541 on a substrate 515 by using this apparatus 500 is described below. First of all, a liquid raw material 522 comprising Cu(hfac)(tmvs) is contained in a raw material vessel 521, and a carrier gas comprising He gas is bubbled therethrough. The raw material evaporated by bubbling and H2 for reduction reaction are passed through flow controllers 503,506 to control their flow rates, respectively, and fed into an inlet vessel 511 having a vaporizer 520 for vaporizing the raw material completely. Thereafter, the resulting precursor 513 is introduced into a reaction vessel 501 through a perforated plate 512. A substrate 515 is disposed beneath perforated plate 512 and placed on a heater 516. In this method, the growth rate and the film quality have been improved by controlling the flow rates of raw material 522 and H2 for reduction reaction and the growth temperature.
However, the above-described prior art involves the following three problems.
First, since this method is based on the utilization of a thermal reaction induced on the substrate surface by heating substrate 515, it has been difficult to improve the rate of film growth.
Secondly, the organometallic complex [e.g., Cu(hfac)(tmvs)] used as the raw material is expensive.
Thirdly, since hexafluoroacetylacetonato (hfac) and trimethylvinylsilane (tmvs) attached to Cu in Cu(hfac)(tmvs) remain in the thin Cu film (constituting thin film 541) as impurities, it has been difficult to improve the film quality.
Moreover, where it is desired to form a metal film (e.g., a thin copper film) by a vapor phase growth process, it has been conventional practice to use a liquid organometallic complex (e.g., copper hexafluoroacetylacetonato-trimethylvinylsilane) as a raw material, dissolve the solid raw material in a solvent, vaporize it, and form a film on a substrate by the utilization of a thermal reaction.
However, since the prior art involves the formation of a film by the utilization of a thermal reaction, it has been difficult to improve the rate of film growth. Moreover, the metal complex used as the raw material is expensive. Furthermore, since hexafluoroacetylacetonato and trimethylvinylsilane attached to Cu remain in the thin Cu film as impurities, it has been difficult to improve the film quality.
Furthermore, a thin copper (Cu) film has conventionally been formed by physical film-forming processes such as vacuum evaporation, ion plating and sputtering, and a chemical vapor phase growth process (CVD process). Among others, the CVD process is widely employed because of its excellent surface covering properties.
According to a conventionally known method for the formation of a thin copper film by the CVD process, a liquid organocopper complex such as copper hexafluoroacetylacetonato-trimethylvinylsilane [hereinafter referred to as Cu(hfac)(tmvs)] is used as a raw material. This raw material is evaporated, carried to a desired surface of a substrate to be treated, and thermally decomposed to form a thin copper film on the substrate surface.
The above-described method for the formation of a thin copper metal is more specifically described with reference to FIG. 23 illustrating an apparatus 600 for the vapor phase growth of a thin copper film. First of all, a substrate 603 to be treated is placed on a flat plate type heater 602 within a reaction vessel 601. The gas within the aforesaid reaction vessel 601 is discharged through an exhaust pipe 604 until a predetermined degree of vacuum is reached. Subsequently, a carrier gas such as He is fed through a pipe 607a and bubbled through a raw material 605 [i.e., Cu(hfac)(tmvs)] contained in a raw material vessel 606. The raw material gas obtained by bubbling and a reducing gas (e.g., hydrogen) are conducted through pipes 607b and 607c, respectively, and fed into a vaporizer 608 disposed in the upper part of the aforesaid reaction vessel 601. The flow rates of the aforesaid raw material gas and hydrogen gas are controlled by flow controllers 609 and 610 installed in the respective pipes 607b and 607c. After the raw material gas is completely vaporized in the aforesaid vaporizer 608, a mixed gas 613 composed of the raw material gas and hydrogen gas is discharged through a plurality of discharge orifices 612 of a discharge plate 611 disposed at the bottom of vaporizer 608 so as to travel toward the aforesaid substrate 603 placed on the aforesaid heater 602. Since the aforesaid substrate 603 is heated to a predetermined temperature by the aforesaid flat plate type heater 602, the aforesaid raw material, or Cu(hfac)(tmvs), is thermally decomposed on the surface of substrate 603 to form a thin copper film 614 thereon. During this film formation, the oxidation of copper is prevented by the reducing action of hydrogen. By controlling the flow rates of the aforesaid raw material and hydrogen and the heating temperature by heater 602, the rate of copper film growth can be regulated and the film quality can be improved.
However, the above-described conventional method for the formation of a thin copper film involves the following three problems.
First, since the above-described method for the formation of a thin copper film is based on the thermal decomposition of vaporized Cu(hfac)(tmvs), it is difficult to improve the rate of film growth. Secondly, the organocopper complex [e.g., Cu(hfac)(tmvs)] used as the raw material is expensive and hence raises the cost of the resulting thin copper film. Thirdly, since hexafluoroacetylacetonato (hfac) and trimethylvinylsilane (tmvs) are incorporated into the thin copper film during its formation and remain therein as impurities, the film quality tends to be reduced.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide methods and apparatus for the formation of a thin noble metal film which can achieve a high rate of film growth, can use inexpensive raw materials, and do not allow any impurities to remain in the thin film.
Another object of the present invention is to provide methods and apparatus for the formation of a metal film which can achieve a high rate of film growth, can use inexpensive raw materials, and do not allow any impurities to remain in the film.
Still another object of the present invention is to provide an apparatus for the vapor phase growth of a thin copper film which uses inexpensive chlorine or hydrogen chloride as a raw material gas, can achieve a high rate of film growth, and can form a thin copper film of good quality containing little residual impurity and having a desired film thickness.
In order to accomplish the above objects, the present invention provides a method for the formation of a metal film which comprises the steps of feeding a raw material gas containing a halogen into an inlet vessel having a perforated plate made of metal; converting the raw material gas into a plasma to generate a raw material gas plasma; etching the perforated plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the perforated plate and the halogen contained in the raw material gas; converting a reducing gas into a plasma to generate a reducing gas plasma; after discharging the precursor from the inlet vessel, passing the precursor through a rotating magnetic field so as to cause the precursor to travel toward a substrate in an accelerated manner; and passing the precursor through the reducing gas plasma to remove the halogen from the precursor and directing the resulting metallic ion or neutral metal onto the substrate to form a thin metal film on the substrate.
The aforesaid metallic ion is a metal atom which has been ionized by the release of an electron or electrons, and the aforesaid neutral metal is a metal atom which has not been ionized.
The aforesaid perforated plate is preferably made of Cu or a noble metal such as Ag, Au or Pt. For example, when a perforated plate made of Cu is used, CuxCly is produced as the aforesaid precursor. Consequently, Cu ions are directed onto the substrate to form a thin Cu film.
Since two plasmas (i.e., the raw material gas plasma and the reducing gas plasma) are used in this method, the reaction efficiency is markedly improved to cause an increase in rate of film growth. Moreover, since a chlorine-containing gas is used as the raw material gas and a hydrogen-containing gas is used as the reducing gas, a marked reduction in cost is achieved. Furthermore, since the reduction reaction can be accelerated independently, the amount of impurities (e.g., chlorine) remaining in the thin film can be minimized to form a thin film of high quality.
According to another embodiment of the present invention, the above objects are accomplished by providing a method for the formation of a metal film which comprises the steps of feeding a raw material gas containing a halogen into an inlet vessel having a perforated plate made of metal; converting the raw material gas into a plasma to generate a raw material gas plasma; etching the perforated plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the perforated plate and the halogen contained in the raw material gas; converting a reducing gas into a plasma to generate a reducing gas plasma; and passing the precursor through the reducing gas plasma to remove the halogen from the precursor and directing the resulting metallic ion or neutral metal onto the substrate to form a thin metal film on the substrate.
The aforesaid perforated plate is preferably made of Cu or a noble metal such as Ag, Au or Pt. For example, when a perforated plate made of Cu is used, CuxCly is produced as the aforesaid precursor. Consequently, Cu ions are directed onto the substrate to form a thin Cu film.
In order to generate the aforesaid reducing gas plasma, there may be used an electrode to which high-frequency electric power is applied. For example, the precursor diffusing toward the aforesaid substrate may be reduced by disposing an electrode opposite to the substrate and generating a plasma all over the electrode.
Since two plasmas (i.e., the raw material gas plasma and the reducing gas plasma) are used in this method, the reaction efficiency is markedly improved to cause an increase in rate of film growth. Moreover, since a halogen-containing gas is used as the raw material gas and a hydrogen-containing gas is used as the reducing gas, a marked reduction in cost is achieved. Furthermore, since the reduction reaction can be accelerated independently, the amount of impurities (e.g., chlorine) remaining in the thin film can be minimized to form a thin film of high quality.
According to still another embodiment of the present invention, there is provided a method for the formation of a metal film which comprises the steps of feeding a raw material gas containing a halogen into an inlet vessel having a perforated plate made of metal; converting the raw material gas into a plasma to generate a raw material gas plasma; etching the perforated plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the perforated plate and the halogen contained in the raw material gas; producing an atomic reducing gas between the perforated plate and a substrate by heating a reducing gas to a high temperature; and, after discharging the precursor from the inlet vessel, passing the precursor through the atomic reducing gas to remove the halogen from the precursor and directing the resulting metallic ion or neutral metal onto the substrate to form a thin metal film on the substrate.
According to this method, the reaction efficiency is markedly improved to cause an increase in rate of film growth. Moreover, since a halogen-containing gas is used as the raw material gas and a hydrogen-containing gas is used as the reducing gas, a marked reduction in cost is achieved. Furthermore, since the reduction reaction can be accelerated independently, the amount of impurities (e.g., chlorine) remaining in the thin film can be minimized to form a thin film of high quality.
According to a further embodiment of the present invention, there is provided a method for the formation of a metal film which comprises the steps of bringing a raw material gas containing a halogen into contact with a hot metallic filament and thereby etching the filament with the raw material gas to produce a precursor composed of the metallic component contained in the filament and the halogen contained in the raw material gas; producing an atomic reducing gas by heating a reducing gas to a high temperature; and passing the precursor through the atomic reducing gas to remove the halogen from the precursor and directing the resulting metallic ion or neutral metal onto a substrate to form a thin metal film on the substrate.
According to the above-described method, the reaction efficiency is markedly improved to cause an increase in rate of film growth. Moreover, since a halogen-containing gas is used as the raw material gas and a hydrogen-containing gas is used as the reducing gas, a marked reduction in cost is achieved. Furthermore, since the reduction reaction can be accelerated independently, the amount of impurities (e.g., chlorine) remaining in the thin film can be minimized to form a thin film of high quality.
According to still a further embodiment of the present invention, there is provided a method for the formation of a metal film which comprises the steps of bringing a raw material gas containing a halogen into contact with a hot metallic filament and thereby etching the filament with the raw material gas to produce a precursor composed of the metallic component contained in the filament and the halogen contained in the raw material gas; utilizing high-frequency electric power for the purpose of converting a reducing gas into a plasma to generate a reducing gas plasma; and passing the precursor through the reducing gas plasma to remove the halogen from the precursor and directing the resulting metallic ion or neutral metal onto a substrate to form a thin metal film on the substrate.
According to the above-described method, the reaction efficiency is markedly improved to cause an increase in rate of film growth. Moreover, since a halogen-containing gas is used as the raw material gas and a hydrogen-containing gas is used as the reducing gas, a marked reduction in cost is achieved. Furthermore, since the reduction reaction can be accelerated independently, the amount of impurities (e.g., chlorine) remaining in the thin film can be minimized to form a thin film of high quality.
In the methods for forming a metal film in accordance with the present invention, a halogen gas, a hydrogen halide gas, or a mixed gas composed of these gases is used as the aforesaid raw material gas. For example, there may be used fluorine gas, chlorine gas, bromine gas, iodine gas, and hydrogen halide gases formed by the combination of these halogens with hydrogen. Among these gases, hydrogen chloride gas has higher reaction efficiency than chlorine gas. consequently, the use of hydrogen chloride gas can decrease the amount of reducing gas used and hence cause a reduction in cost.
Moreover, the above-described steps extending from the feeding of a raw material gas to the production of a precursor may be replace by a method comprising the step of bubbling a carrier gas (e.g., He) through a liquid organometallic complex to evaporate it, and the step of vaporizing the evaporated organometallic complex in a vaporizer or the like and introducing the resulting vapor into the reaction vessel.
According to these methods, the reducing gas plasma decomposes the impurities (e.g., halogen compounds and carbon compounds) contained in the raw material gas, the amount of impurities remaining in the thin metal film can be reduced.
According to the present invention, there is also provided an apparatus for the formation of a metal film which comprises an inlet vessel equipped with a metallic perforated plate having discharge orifices bored therethrough and adapted to receive a raw material gas in its internal volume; a first plasma generator for converting the raw material gas received in the inlet vessel into a plasma and thereby generating a raw material gas plasma; a reaction vessel housing the inlet vessel and a substrate; a rotating magnetic field generator for creating a rotating magnetic field between the perforated plate and the substrate; and a second plasma generator for generating a plasma from a reducing gas fed into the reaction vessel.
As the aforesaid rotating magnetic field generator, there may be used, for example, a device comprising a rotating magnetic field coil disposed on the side of the reaction vessel, and a power supply for passing a high electric current through the rotating magnetic field coil.
According to another embodiment of the present invention, there is provided an apparatus for the formation of a metal film which comprises an inlet vessel equipped with a metallic perforated plate having discharge orifices bored therethrough and adapted to receive a raw material gas in its internal volume; a first plasma generator for converting the raw material gas received in the inlet vessel into a plasma and thereby generating a raw material gas plasma; a reaction vessel housing the inlet vessel and a substrate; and a meshlike, ladderlike or comblike electrode for generating a plasma from a reducing gas fed into the reaction vessel by applying high-frequency electric power thereto.
By providing the electrode surface with holes or openings, the flux of the precursor can be subjected to a reduction reaction uniformly, without preventing the precursor from traveling toward the substrate.
According to still another embodiment of the present invention, there is provided an apparatus for the formation of a metal film which comprises an inlet vessel equipped with a metallic perforated plate having discharge orifices bored therethrough and adapted to receive a raw material gas in its internal volume; a plasma generator for converting the raw material gas received in the inlet vessel into a plasma and thereby generating a raw material gas plasma; a reaction vessel housing the inlet vessel and a substrate; and a reducing gas heating device for heating a reducing gas fed into the reaction vessel.
As the aforesaid reducing gas heating device, there may preferably be used, for example, a tungsten filament heated to a high temperature by passing a high electric current therethrough. When a reducing gas is made to flow through the filament, an atomic reducing gas is produced.
According to a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film which comprises a precursor feeding device for bringing a raw material gas into contact with a hot metallic filament to produce a precursor and feeding the precursor into a reaction vessel; the reaction vessel housing a substrate; and a reducing gas heating device for heating a reducing gas fed into the reaction vessel.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film which comprises a precursor feeding device for bubbling a carrier gas through a liquid organometallic complex, vaporizing the organometallic complex, producing a precursor from the vaporized organometallic complex, and feeding the precursor into a reaction vessel; the reaction vessel housing a substrate; a rotating magnetic field generator for creating a rotating magnetic field in a space above the substrate; and a second plasma generator for generating a plasma from a reducing gas fed into the reaction vessel.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film which comprises a precursor feeding device for bubbling a carrier gas through a liquid organometallic complex, vaporizing the organometallic complex, producing a precursor from the vaporized organometallic complex, and feeding the precursor into a reaction vessel; the reaction vessel housing a substrate; and a meshlike, ladderlike or comblike electrode for generating a plasma from a reducing gas fed into the reaction vessel by applying high-frequency electric power thereto.
By employing these methods and apparatus for the formation of a metal film in accordance with the present invention, a thin metal film of high quality showing no precipitation of impurities can be rapidly formed at low cost.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; second plasma generating means for converting a hydrogen-containing reducing gas within the chamber into a plasma to generate a reducing gas plasma; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor is passed through the reducing gas plasma within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; and second plasma generating means for converting a hydrogen-containing reducing gas within the chamber into a plasma to generate a reducing gas plasma; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the reducing gas plasma to remove chlorine from the precursor by reduction, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; second plasma generating means for converting a hydrogen-containing reducing gas within the chamber into a plasma to generate a reducing gas plasma; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the reducing gas plasma to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor is passed through the atomic reducing gas within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; and reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the atomic reducing gas to remove chlorine from the precursor by reduction, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the atomic reducing gas within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising precursor feeding means for bringing a chlorine-containing raw material gas into contact with a hot metallic filament to produce a precursor within a chamber housing a substrate, the precursor being composed of the metallic component contained in the metallic filament and the chlorine contained in the raw material gas; reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor is passed through the atomic reducing gas within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate.
In these apparatus, the discharge plate or metallic filament may be made of copper, so that CuxCly is produced as the aforesaid precursor. Moreover, the discharge plate may be made of copper and the predetermined temperature to which the discharge plate is heated by the discharge plate heating means may be in the range of 200 to 800xc2x0 C. Furthermore, the discharge plate heating means may comprise means for heating the discharge plate by introducing a rare gas into the inlet vessel, using the first plasma generating means to generate a rare gas plasma, and applying a voltage so as to cause the rare gas component ion to collide with the discharge plate.
In this case, the predetermined temperature is preferably 600xc2x0 C. When CuxCly is produced as the aforesaid precursor, the predetermined temperature to which the chamber is heated by the chamber heating means is preferably about 200xc2x0 C. In addition to Cu, Ag, Au, Pt, Ti, W and the like may be used for the discharge plate or metallic filament. As the raw material gas, there may be used chlorine gas, hydrogen chloride gas or a mixed gas composed of these gases.
In order to accomplish the above objects, the present invention also provides a method for the formation of a metal film which comprises reacting chlorine with a metallic plate within a chamber to produce a precursor composed of a metallic component and chlorine, removing chlorine from the precursor by reduction, and directing the resulting metallic ion onto a substrate within the chamber to form a metal film on the substrate, the method being characterized in that the chamber is heated to a predetermined temperature so as to prevent the precursor from depositing on the inner wall of the chamber.
In order to accomplish the above objects, the present invention also provides a method for the formation of a metal film which comprises reacting chlorine with a metallic plate within a chamber to produce a precursor composed of a metallic component and chlorine, removing chlorine from the precursor by reduction, and directing the resulting metallic ion onto a substrate within the chamber to form a metal film on the substrate, the method being characterized in that the metallic plate is heated to a predetermined temperature so as to make the precursor easy to reduce.
According to another embodiment of the present invention, the above objects are accomplished by providing a method for the formation of a metal film which comprises reacting chlorine with a metallic plate within a chamber to produce a precursor composed of a metallic component and chlorine, removing chlorine from the precursor by reduction, and directing the resulting metallic ion onto a substrate within the chamber to form a metal film on the substrate, the method being characterized in that the chamber is heated to a predetermined temperature so as to prevent the precursor from depositing on the inner wall of the chamber and, moreover, the metallic plate is heated to a predetermined temperature so as to make the precursor easy to reduce.
In these methods, the metallic plate may be made of copper, so that CuxCly is produced as the aforesaid precursor.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; second plasma generating means for converting a hydrogen-containing reducing gas within the chamber into a plasma to generate a reducing gas plasma; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor is passed through the reducing gas plasma within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate. Thus, the precursor is prevented from depositing on the inner wall of the chamber. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, the necessity of cleaning the inside of the chamber periodically can be eliminated to cause an improvement in raw material efficiency and a reduction in running cost.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; and second plasma generating means for converting a hydrogen-containing reducing gas within the chamber into a plasma to generate a reducing gas plasma; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the reducing gas plasma to remove chlorine from the precursor by reduction, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate. Thus, a monomeric precursor which can be easily reduced tends to be produced. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, chlorine can be removed by reduction in a short period of time, resulting in a further improvement in the rate of film growth.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; second plasma generating means for converting a hydrogen-containing reducing gas within the chamber into a plasma to generate a reducing gas plasma; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the reducing gas plasma to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate. Thus, the precursor is prevented from depositing on the inner wall of the chamber and, moreover, a monomeric precursor which can be easily reduced tends to be produced. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, the necessity of cleaning the inside of the chamber periodically can be eliminated to cause an improvement in raw material efficiency and a reduction in running cost. Furthermore, chlorine can be removed by reduction in a short period of time, resulting in a further improvement in the rate of film growth.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor is passed through the atomic reducing gas within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate. Thus, the precursor is prevented from depositing on the inner wall of the chamber. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, the necessity of cleaning the inside of the chamber periodically can be eliminated to cause an improvement in raw material efficiency and a reduction in running cost.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; and reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the atomic reducing gas to remove chlorine from the precursor by reduction, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate. Thus, a monomeric precursor which can be easily reduced tends to be produced. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, chlorine can be removed by reduction in a short period of time, resulting in a further improvement in the rate of film growth.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising an inlet vessel equipped with a metallic discharge plate having a multitude of discharge orifices bored therethrough and adapted to receive a chlorine-containing raw material gas in its internal volume; discharge plate heating means for heating the discharge plate to a predetermined temperature; a chamber housing the inlet vessel and a substrate; first plasma generating means for converting the raw material gas within the inlet vessel into a plasma to generate a raw material gas plasma, and thereby etching the discharge plate with the raw material gas plasma to produce a precursor composed of the metallic component contained in the discharge plate and the chlorine contained in the raw material gas; reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor, which has been produced by etching the heated discharge plate and is hence easy to reduce, is passed through the atomic reducing gas within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate. Thus, the precursor is prevented from depositing on the inner wall of the chamber and, moreover, a monomeric precursor which can be easily reduced tends to be produced. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, the necessity of cleaning the inside of the chamber periodically can be eliminated to cause an improvement in raw material efficiency and a reduction in running cost. Furthermore, chlorine can be removed by reduction in a short period of time, resulting in a further improvement in the rate of film growth.
According to still a further embodiment of the present invention, the above objects are accomplished by providing an apparatus for the formation of a metal film, the apparatus comprising precursor feeding means for bringing a chlorine-containing raw material gas into contact with a hot metallic filament to produce a precursor within a chamber housing a substrate, the precursor being composed of the metallic component contained in the metallic filament and the chlorine contained in the raw material gas; reducing gas heating means for heating a hydrogen-containing reducing gas to a high temperature and thereby producing an atomic reducing gas within the chamber between the substrate and the discharge plate; and chamber heating means for heating the chamber to a predetermined temperature; whereby the precursor is passed through the atomic reducing gas within the chamber to remove chlorine from the precursor by reduction, without allowing the precursor to deposit on the heated inner wall of the chamber, and the resulting metallic ion is directed onto the substrate to form a metal film on the substrate. Thus, the precursor is prevented from depositing on the inner wall of the chamber. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, the necessity of cleaning the inside of the chamber periodically can be eliminated to cause an improvement in raw material efficiency and a reduction in running cost.
According to still a further embodiment of the present invention, there is provided a method for the formation of a metal film which comprises reacting chlorine with a metallic plate within a chamber to produce a precursor composed of a metallic component and chlorine, removing chlorine from the precursor by reduction, and directing the resulting metallic ion onto a substrate within the chamber to form a metal film on the substrate, the method being characterized in that the chamber is heated to a predetermined temperature so as to prevent the precursor from depositing on the inner wall of the chamber. Thus, the precursor is prevented from depositing on the inner wall of the chamber. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, the necessity of cleaning the inside of the chamber periodically can be eliminated to cause an improvement in raw material efficiency and a reduction in running cost.
According to still a further embodiment of the present invention, there is provided a method for the formation of a metal film which comprises reacting chlorine with a metallic plate within a chamber to produce a precursor composed of a metallic component and chlorine, removing chlorine from the precursor by reduction, and directing the resulting metallic ion onto a substrate within the chamber to form a metal film on the substrate, the method being characterized in that the metallic plate is heated to a predetermined temperature so as to make the precursor easy to reduce. Thus, a monomeric precursor which can be easily reduced tends to be produced. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, chlorine can be removed by reduction in a short period of time, resulting in a further improvement in the rate of film growth.
According to still a further embodiment of the present invention, there is provided a method for the formation of a metal film which comprises reacting chlorine with a metallic plate within a chamber to produce a precursor composed of a metallic component and chlorine, removing chlorine from the precursor by reduction, and directing the resulting metallic ion onto a substrate within the chamber to form a metal film on the substrate, the method being characterized in that the chamber is heated to a predetermined temperature so as to prevent the precursor from depositing on the inner wall of the chamber and, moreover, the metallic plate is heated to a predetermined temperature so as to make the precursor easy to reduce. Thus, the precursor is prevented from depositing on the inner wall of the chamber and, moreover, a monomeric precursor which can be easily reduced tends to be produced. Consequently, a high rate of film growth can be achieved, an inexpensive raw material can be used, and an apparatus for the formation of a metal film containing no residual impurities can be obtained. Moreover, the necessity of cleaning the inside of the chamber periodically can be eliminated to cause an improvement in raw material efficiency and a reduction in running cost. Furthermore, chlorine can be removed by reduction in a short period of time, resulting in a further improvement in the rate of film growth.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising:
a reaction vessel in which a substrate to be treated is placed;
an inlet vessel disposed within the reaction vessel and equipped with a copper discharge plate having a plurality of discharge orifices bored therethrough;
temperature control means attached to the copper discharge plate;
a raw material gas feed pipe inserted into the inlet vessel for feeding chlorine or hydrogen chloride;
plasma generating means for generating a plasma of chlorine or hydrogen chloride within the inlet vessel;
atomic reducing gas producing means for producing an atomic reducing gas within the reaction vessel, at least in the neighborhood of the substrate to be treated; and
evacuation means for evacuating any gas from the reaction vessel and the inlet vessel.
According to still a further embodiment of the present invention, there is provided an apparatus for the formation of a metal film, the apparatus comprising:
a reaction vessel in which a substrate to be treated is placed;
a raw material gas feed pipe inserted into the inlet vessel for feeding chlorine or hydrogen chloride;
a spiral tube attached to the inner end of the raw material gas feed pipe, having a raw material gas flow passage whose inner surface is made of copper, and equipped with a heating element;
atomic reducing gas producing means for producing an atomic reducing gas within the reaction vessel, at least in the neighborhood of the substrate to be treated; and
evacuation means for evacuating any gas from the reaction vessel and the raw material gas flow passage.
As specifically described above, the present invention makes it possible to achieve a high rate of film growth while using inexpensive chlorine or hydrogen chloride as a raw material gas, and to form a thin copper film of good quality containing little residual impurities and having a desired film thickness, with good reproducibility. Thus, the present invention can provide an apparatus for the vapor phase growth of a thin copper film which is useful, for example, in the formation of wiring material films for use in semiconductor devices and liquid crystal displays.